Method of producing 6-substituted (s)-nicotine derivatives and intermediate compounds

ABSTRACT

A method of producing a 6-substituted (S)-nicotine derivative with the general formula (III), wherein R is an optionally substituted alkyl, alkenyl, alkynyl, amido or amino group, optionally coupled to a carrier protein, is disclosed. An intermediate compound useful in the method is also comprised by the invention. The formula of the compound is (A) in which A represents the cationic radical of an organic nitrogen base, Y represents an anion formed by an electrophilic compound.

The present invention relates to a method of producing enantiomericallypure 6-substituted (S)-nicotine derivatives and to new intermediatecompounds for use in said method.

BACKGROUND OF THE INVENTION

There are several patent applications and published articles directed tovaccines/immunogens against nicotine dependency/harm reduction, but nosuch vaccines/immunogens are yet on the market.

One approach is directed to a vaccine/immunogen that in an individualcan elicit antibodies which strongly bind to administered/inhalednicotine and block its effect before it reaches the central nervoussystem. The desired result is that the individual will not experiencethe expected stimulating effect of nicotine administration/smoking, andtherefore the interest in administering a tobacco product, such as moistsnuff, or lighting a cigarette will cease (extinction/prevention).

A complementary approach is directed to an immunogen that in anindividual can elicit antibodies which moderately or weakly bind toadministered/inhaled nicotine and enhance/prolong its effect in thecentral nervous system. The desired result is that the individual willexperience the expected stimulating effect of nicotineadministration/smoking during a prolonged period of time, and thereforethe interest in a renewed administration of a tobacco product, such asmoist snuff, or lighting a cigarette will be postponed and the medicalconsequences of the tobacco product consumption will be reduced.

Both of the above mentioned approaches use immunogens which in anindividual induces an immunological response which leads to harmreduction.

Papers disclosing active immunization to alter nicotine distribution wasrecently published (Hieda Y. et al, J. Pharmacol. Exp. Therap. 1997,283, 1076-1081, Pentel, P. R. et al, Pharmacol. Biochem. Behav. 2000,65, 191-198). The immunogens used in the Hieda and Pentel articles were(±)-6-(carboxymethyl-ureido)-nicotine conjugated to keyhole limpethemocyanin and (±)-trans-3′-aminomethylnicotine conjugated toPseudomonas aerigunosa exoprotein A via a succinic acid linker,respectively.

The international patent application WO 98/14216 claims a large numberof hapten-carrier conjugates based on the nicotine molecule and thecommon structural feature of the compounds seems to be that all of thehapten molecules contain a terminal carboxylic acid group which is thenconjugated to the carrier. No in vivo testing has been disclosed for thealleged drug abuse treatment.

Other nicotine derivatives useful in vaccines/immunogens are comprisedby the present inventors' International patent application WO9961054A1directed to nicotine immunogens comprising 5- or6-nicotinyl-linker-carrier proteins.

All the published 6-nicotine derivatives are produced as racemates, andif an enantiomer is desired, the production is accomplished byprocedures for separating racemic mixtures into optically pure fractionswell known in the art (see for example U.S. Pat. No. 5,420,286) giving≦50% of each enantiomer.

However, it should be noted that all tobacco products contain the(S)-nicotine enantiomer only. Therefore, it is desirable to useenantiomerically pure (S)-nicotine derivatives in the differentprophylactic and therapeutic applications.

DESCRIPTION OF THE INVENTION

The present invention provides a new method of producingenantiomerically pure 6-substituted (S)-nicotine derivatives in goodyields and high enantiomeric purity and new intermediate compounds foruse in said method.

More specifically, the present invention is directed to a method ofproducing a 6-substituted (S)-nicotine derivative with the generalformula (III),

wherein R is an optionally substituted alkyl, alkenyl, alkynyl, amido oramino group.

The method comprises the steps of

a) reacting (S)-nicotine-N1-oxide with an organic nitrogen base A,selected from trialkylamine, dialkylbenzylamine, dialkylcyclohexylamineand pyridine in which the alkyl groups may be individually selected fromlower alkyl groups, and an electrophilic compound, if appropriate in thepresence of a organic solvent to produce a (S)-nicotine derivative withthe general formula

wherein

A represents a cationic radical of the organic nitrogen base, and

Y represents an anion formed by the electrophilic compound,

b) reacting the compound (I) with a nucleophilic reagent to produce the(S)-nicotine derivative with the general formula

wherein Nu represents the nucleophile, and reacting the compound (II)with an optionally substituted alkyn to produce a 6-substituted(S)-nicotine derivative with the formula (III) wherein R is anoptionally substituted alkyn group, followed by the optional steps ofhydrogenation of the triple bond of the alkyne to produce a compoundwith the formula (III) wherein R is an alkyl or alkenyl group orreacting the compound (II) with an amide anion to produce(S)-6-aminonicotine which then is coupled with an optionally substitutedcarboxylic acid to produce a 6-substituted (S)-nicotine derivative withthe formula (III) wherein R is an optionally substituted amido groupfollowed by the optional step of reduction of the amide to produce acompound with the formula (III) wherein R is an amino group.

In a preferred embodiment the produced compounds are those wherein thesubstituent R is

—X—Y—Z-Q

wherein

X is —NH—CO— or —NH— or —C≡C— or —C≡C— or —CH₂—;

Y is —(CH₂)_(k)— or (CH₂)_(m)—C₆H₁₀(CH₂)_(n)— or(CH₂)_(m)—C₆H₄—(CH₂)_(n)—

wherein k=0-20, m=0-6, and n=0-6, when

Z is —NH— and Q is H

and

X is —NH—CO— or —C≡C— or —C═C— or —CH₂—,

Y is —(CH₂)_(m)—C₆H₁₀—(CH₂)_(n)— or (CH₂)_(m)—C₆H₄(CH₂)_(n)—

wherein m=0-6, and n=0-6, when

Z is —CO— and Q is —OH

and

X is —C≡C— or —C═C—,

Z is —CO— and Q is —OH, when

Y is —(CH₂)_(k)—

wherein k=0-20.

These compounds are, in racemic form, comprised by our earlierinternational patent application WO 9961054.

In another preferred embodiment A represents an organic nitrogen baseselected from the group consisting of: trialkylamine,dialkylbenzylamine, dialkylcyclohexylamine and pyridine in which thealkyl groups may be individually selected from lower alkyl groups, and Yrepresents an arylsulphonate ion, a chloride ion or a loweralkylcarboxylate ion.

In a most preferred embodiment A represents trimethylamine,triethylamine, tripropylamine, tributylamine, N,N-dimethylbenzylamine,N,N-diethylbenzylamine, N,N-dimethylcyclohexylamine andN,N-diethylcyclohexylamine, and Y represents a benzenesulphonate ion, achloride ion or an acetate ion.

In yet another embodiment of the method off the invention thenucleophilic reagent is selected from the group consisting ofhalogenating agents.

The present invention is also directed to the intermediate compound ofthe formula

in which

A represents the cationic radical of an organic nitrogen base

Y represents an anion formed by an electrophilic compound.

Also in this aspect of the invention A preferably represents an organicnitrogen base selected from the group consisting of: trialkylamine,dialkylbenzylamine, dialkylcyclohexylamine and pyridine, in which thealkyl groups may be individually selected from lower alkyl groups, and Yrepresents an arylsulphonate ion, a chloride ion or a loweralkylcarboxylate ion. Most preferably A represents trimethylamine,triethylamine, tripropylamine, tributylamine, N,N-dimethylbenzylamine,N,N-diethylbenzylamine, N,N-dimethylcyclohexylamine andN,N-diethylcyclohexylamine, and Y represents a benzenesulphonate ion, achloride ion or an acetate ion.

The 6-substituted (S)-nicotine derivatives produced by the method of theinvention may be coupled to carrier proteins in the same way asdisclosed in our international patent application WO 9961054. Examplesof suitable carrier proteins are keyhole limpet hemocyanin (KLH),tetanus toxoid, diphtheria toxoid, non-toxic mutant diphtheria toxoidCRM₁₉₇, outer membrane protein complex (OMPC) from Neisseriameningitidis, the B subunit of heat-labile Escherichia coli, andrecombinant exoprotein A from Pseudomonas aeruginosa (rEPA).

The 6-substituted (S)-nicotine derivatives produced by the method of theinvention coupled to carrier proteins will find use asvaccines/immunogens for prophylactic and/or therapeutic immunologicaltreatment of nicotine dependence from tobacco products to achieve harmreduction in an individual.

The present invention will now be further illustrated by reference tothe following description of synthesis of typical examples ofintermediate compounds and end products. However, these illustratedembodiments are not to be considered as limitations to the scope of theinvention defined in the claims.

Description of Synthesis of Compounds

The starting material for the synthesis, (S)-nicotine mono-N1-oxide, isobtained from (S)-nicotine as previously described in the literature,and all the other chemicals used in the illustrated syntheses are eitherbought or synthesized as previously described in our internationalpatent application WO 9961054.

In the following Scheme 1 the synthetic pathway for producing thecompounds of the structural formulae (I)-(III) is illustrated withexemplary compounds. The 6-substituted (S)-nicotine compounds 5-10 aredisclosed, as racemates, in our international patent application WO9961054.

(S)-Trimethyl-[5-(1-methyl-pyrrolidin-2-yl)-pyridin-2-yl]ammoniumBenzenesulfonate (1).

Trimethylamine (5.9 g, 0.1 mol) was condensed at −25° C. into a stirredsolution of (S)-nicotine mono-N1-oxide¹ (1.77 g, 0.01 mol) in dry CH₂Cl₂(20 mL). A solution of benzenesulfonyl chloride (3.7 g, 0.02 mol) in dryCH₂Cl₂ (15 mL) was added dropwise at −15° C., over a period of 60 min.The mixture was stirred at this temperature for 60 min and then allowedto reach room temperature. After 3 h at room temperature, the reactionmixture was concentrated in vacuo. The residue was treated with CH₂Cl₂(50 mL) and most of the trimethylamine hydrochloride was filtered offand the solution was concentrated in vacuo. The residue was purified byflash chromatography [Al₂O₃, CHCl₃, then CHCl₃/MeOH, (15:1)], to yield2.86 g (76%) of product. An analytical sample was obtained bycrystallization from MeOH/benzene.

¹Taylor, E. C. and Boyer, N. E. J. Org. Chem. 1959, 24, 275-277.

Anal. Calcd. for C₁₉H₂₇N₃SO₃.0.25H₂O: C, 59.7; H, 7.3; N, 11.0. Found:C, 59.7; H, 7.2; N, 10.9; mp (MeOH/benzene): 149.0-151.0° C. (dec);[α]_(D) ^(rt) −60.0° [c 0.9, MeOH]

¹H NMR (270 MHz, CDCl₃): δ 8.46 (br s, 1H); 8.25 (d, J=8.5 Hz, 1H); 7.88(m, 3H); 7.33 (m, 3H); 3.84 (s, 9H); 3.27 (br t, J=7.5 Hz, 2H); 2.40(dd, J=17.5, 8.5 Hz, 1H); 2.24(m, 4H); 1.89 (m, 2H); 1.66 (m, 1H). ¹³CNMR (68 MHz, CDCl₃): δ 156.2, 148.2, 146.7, 140.7, 2×129.6, 2×128.3,126.1, 115.4, 67.9, 56.9, 3×55.5, 40.2, 35.1, 22.8, 1.2.

(S)-6-Chloronicotine (2)².

²Roduit, J. P.; Wellig, A.; Kiener, A. Heterocycles, 1997, 45,1687-1702.

A solution of 1 (130 mg, 0.3 mmol) in dry 1,2-dichloroethane (10 mL) wassaturated with HCl (g), and the reaction mixture was stirred at 35° C.for 22 h. The solvent was evaporated in vacuo. The residue was dissolvedin CH₂Cl₂ and the pH of the mixture was brought to pH˜7-8 by addition ofsaturated aq NaHCO₃. The organic layer was washed with brine, dried(MgSO₄), filtered and concentrated in vacuo to yield a brownish oil. Theoil was chromatographed [Al₂O₃, iso-hexane/AcOEt, (4:1)] to afford 53.3mg (78%) of 2 as a pink oil. [α]_(D) ²³ −154.3° (c 1.0 MeCN) [lit.²[α]_(D) ²³ −154° (c 1.0 MeCN)].

(S)-6-Bromonicotine (3).

A solution of 1 (1.1 g, 2.9 mmol) in dry CH₂Cl₂ (50 mL) was saturatedwith HBr [(g) dried with Mg(ClO₄)₂], and the reaction mixture wasstirred at ambient temperature for 30 h. The solvent was evaporated invacuo. The residue was dissolved in CH₂Cl₂ and the pH of the mixture wasbrought to pH˜7-8 by addition of saturated aq NaHCO₃. The organic layerwas washed with brine, dried (MgSO₄), filtered and concentrated in vacuoto yield a brownish oil. The residue was chromatographed [Al₂O₃,iso-hexane/AcOEt (4:1)] to afford 0.53 g (75%) of 3 as a colorless oil(turns reddish with time).

3: ¹H NMR (270 MHz, CDCl₃): δ 8.27 (d, 1H; J=2.5 Hz); 7.57 (dd, 1H;J=8.3, 2.5 Hz); 7.42 (dd, 1H; J 8.6, 0.3 Hz); 3.21 (ddd, 1H; J=8.6, 8.6,2.2 Hz); 3.06 (brt, 1H; J=8.3 Hz); 2.30 (dd, 1H; J=17.6, 9.2 Hz); 1.88(m, 2H); 2.18 (m, 4H); 1.66 (m, 1H). ¹³C NMR (68 MHz, CDCl₃): δ 149.6,140.5, 138.4, 137.8, 128.0, 67.9, 56.8, 40.2, 35.2, 22.6.

MS (EI, 70 eV) m/z 240; 242 (1:1) (M⁺); [α]_(D) ^(rt) −132.5° (c 1,CH₃CN); The enantiomeric purity was determined by chiral HPLC.

Treatment of 3 with picric acid in EtOH:H₂O yielded the monopicrate salt3 monopicrate: mp (EtOH/H₂O) 141.0-143.0° C.

Anal. Calcd. for C₁₆H₁₆N₅O₇Br: C, 40.9; H, 3.4; N, 14.9. Found: C, 40.4;H, 3.4; N, 14.7.

3 monopicrate salt: ¹H NMR (270 MHz, CD₃COCD₃): δ 8.75 (s, 2H); 8.61 (d,1H; J=2.6 Hz); 8.15 (dd, 1H, J=8.4, 2.6 Hz); 7.64 (d, 1H; J=8.4 Hz);4.68 (brs, 1H); 4.08 (br s, 1H); 3.57 (m, 1H); 3.03 (s, 3H); 2.54 (m,4H). ¹³C NMR (68 MHz, CD₃COCD₃): δ 162.5, 152.3, 144.3, 142.9, 2×140.3,129.5, 128.4, 2×126.5, 70.8, 57.6, 39.8, 31.7, 22.4.

(S)-6-Aminonicotine (4)³.

³Gol'dfarb, Ya. L. and Smorgonskii, L. M. Izvest. Akad. Nauk S.S.S.R.Otdel. Khim. Nauk 1946, 557.

Potassium metal (78 mg, 2 mmol) was added to ˜15 mL of NH₃ followed by5-10 mg of Fe NO₃)₃ 9H₂O to catalyze amide formation. After thepotassium amide had formed (gray suspension), a solution of 3 (120 mg,0.5 mmol) in dry ether (5 mL) was added. The mixture was stirred for 20min and quenched with excess of solid NH₄Cl. Ammonia was evaporated andthe solid residue was treated with saturated aq. K₂CO₃ and extractedwith ether (5×5 mL). The combined ether extracts was dried with KOH andthen evaporated. The residue was purified by column chromatography[silica, CHCl₃/MeOH saturated with ammonia, (20:1)] to give 54 mg (61%)of 4: mp 66-67° C.; [α]_(D) ^(rt)=−120.1 (c 1, MeOH).

4: ¹H NMR (270 MHz, CDCl₃): δ 7.95 (d, 1H; J=2.0 Hz); 7.5 (dd, 1H;J=8.4; 2.3 Hz); 6.51 (d, 1H; J 8.4 Hz); 4.44 (brs, 2H); 3.22 (ddd, 1H;J=9.6, 9.6, 2.0 Hz); 2.94 (brt, 1H; J=8.3 Hz); 2.25 (dd, 1H; J=17.5, 9.1Hz); 2.09 (m, 4H); 1.94 (m, 1H); 1.76 (m, 2H).

¹³C NMR (68 MHz, CDCl₃) δ 158.1, 147.4, 137.2, 128.2, 109.1, 68.7, 57.0,40.3, 34.7, 22.4.

MS (EI, 70 eV) m/z 177 (M+). The enantiomeric purity was determined bychiral HPLC.

(S)-trans-4-[3-(5-(1-Methyl-2-pyrrolidinyl)-2-pyridinyl)prop-2-ynyl]cyclohexanecarboxylicAcid Methyl Ester (5).

A mixture of 3 (0.2 g, 0.8 mmol), bis(triphenylphosphine)palladiumdichloride (0.014 g, 0.02 mmol) and CuI (0.004 g, 0.02 mmol) in 5 mL ofEt₃N was deoxygenated with N₂. trans-4-Prop-2-ynylcyclohexancarboxylicacid methyl ester⁴ (0.2 g, 1.1 mmol) was added and the reaction mixturewas heated at 120° C. for 45 min in a sealed vessel. The Et₃N wasevaporated in vacuo and the residue was dissolved in EtOAc, washed withsaturated aqueous NaHCO₃ and extracted with 2×15 mL of 2N HCl. Theacidic aqueous phase was extracted with EtOAc (3×20 mL). The aqueouslayer was saturated with solid NaHCO₃ and extracted with EtOAc (3×20mL). The organic phase was washed with brine, dried (Na₂SO₄), filteredand concentrated in vacuo. The residue was chromatographed [silica,acetone/iso-hexane (1:2)] to yield 0.26 g (93%) of 5.

⁴Svensson, T. and Johansson, A. WO9961054A1, 1999.

IR (film) ν_(max) 2226 cm⁻¹. ¹H NMR (CDCl₃, 270 MHz) δ 8.40 (br s, 1H),7.63 (dd, J=8.1; 2.0 Hz, 1H), 7.30 (d, J=8.1 Hz, 1H), 3.60 (s, 3H),3.25-3.18 (m, 1H), 3.08 (app t, 1H), 2.31-2.08 (m, 5H), 2.12 (s, 3H),1.98-1.32 (m, 10H), 1.15-0.99 (m, 2H); ¹³C NMR (CDCl₃, 68 MHz) δ 176.4,149.6, 142.8, 137.2, 135.1, 126.9, 89.0, 81.6, 68.8, 56.9, 51.6, 43.0,40.2, 36.5, 35.0, 31.7, 28.8, 26.8, 22.6. MS (EI, 70 eV) m/z 340 (M⁺)Anal. Calcd. for C₂₁H₂₈N₂O₂: C, 74.09; H, 8.29; N, 8.23%. Found: C,73.84; H, 8.27; N, 8.32%.

[α]_(D) ^(rt)=−84.0 (c 1, MeOH)

(S)-trans-4-[3-(5-(1-Methyl-2-pyrrolidinyl)-2-pyridinyl)propyl]cyclohexanecarboxylicAcid Methyl Ester (6).

A solution of 5 (0.13 g, 0.4 mmol) in MeOH (40 mL) was hydrogenated atroom temperature and atmospheric pressure over 10% Pd/C (0.06 g). After40 min the catalyst was filtered off and washed with MeOH. The volatileswas evaporated under reduced pressure and the residue waschromatographed [SiO₂, acetone/iso-hexane (1:2)] to afford 0.13 g (93%)of 6.

¹H NMR (CDCl₃, 270 MHz) δ 8.39 (d, J=2.0 Hz, 1H), 7.67 (dd, J=7.9; 1.8Hz, 1H), 7.10 (d, J=7.9 Hz, 1H), 3.62 (s, 3H), 3.31-3.25 (m, 1H), 3.12(app t, 1H), 2.72 (t, J=7.7 Hz, 2H), 2.39-2.12 (m, 2H), 2.18 (s, 3H),2.02-1.65 (m, 9H), 1.44-1.29 (m, 2H), 1.30-1.22 (m, 3H), 0.96-0.80 (m,2H); ¹³C NMR (CDCl₃, 68 MHz) δ 176.8, 161.8, 149.1, 135.5, 134.6, 122.9,69.0, 57.0, 51.6, 43.6, 40.2, 38.5, 37.1, 37.0, 34.8, 32.4, 29.1, 27.4,22.5. MS (EI, 70 eV) m/z 344 (M⁺) Anal. Calcd. for C₂₁H₃₂N₂O₂x0.2H₂O: C,72.46; H, 9.37; N, 8.05%. Found: C, 72.34; H, 9.44; N, 8.06%; [α]_(D)^(rt)=−61.0 (c 1, MeOH).

(S)-trans-4-[3-(5-(1-Methyl-2-pyrrolidinyl)-2-pyridinyl)propyl]cyclohexanecarboxylicAcid (7).

A mixture of 6 (0.11 g, 0.3 mmol) and KOH (0.025 g, 0.45 mmol) in 50%aqueous MeOH (10 mL) was heated under reflux for 30 min. The reactionmixture was acidified with HOAc to pH 8 and the solvents were evaporatedin vacuo. The crude product was purified by column chromatography(silica gel, CHCl₃/MeOH, gradient of MeOH 10% to 50%) to afford 0.077 g(74%) of 7.

¹H NMR (CD₃OD, 270 MHz) δ 8.44 (br s, 1H), 7.83 (dd, J=8.1; 2.2 Hz, 1H),7.34 (d, J=8.1 Hz, 1H), 3.50 (app t, 1H), 3.43-3.35 (m, 1H), 2.77 (t,7.7 Hz, 2H), 2.66-2.56 (m, 1H), 2.40-2.26 (m, 1H), 2.31 (s, 3H),2.11-1.67 (m, 10H), 1.45-1.23 (m, 5H), 0.98-0.86 (m, 2H); ¹³C NMR(CDCl₃, 68 MHz) δ 184.0, 163.5, 149.6, 138.1, 134.6, 124.8, 70.3, 57.7,40.2, 38.8, 38.5, 38.2, 34.7, 33.9, 31.0, 28.6, 23.2; [α]_(D)^(rt)=−49.0 (c 2, MeOH).

(S)-2-(3-Hydroxy-3-methylbut-1-ynyl)-5-(1-methyl-2-pyrrolidinyl)pyridine(8).

A mixture of 3 (0.2 g, 0.8 mmol), triphenylphosphine (0.022 g, 0.08mmol), 10% Pd/C (0.022 g, 0.021 mmol in Pd), CuI (0.016 g, 0.08 mmol)and K₂CO₃ (0.24 g, 2.0 mmol) in 30 mL of a mixture DME/H₂O (1:1) wasdeoxygenated with N₂. The mixture was stirred at room temperature for 30min and then 2-methyl-3-butyn-2-ol (0.17 g, 2.0 mmol) was added. Afterstirring under reflux for 7 h the mixture was filtered over a celite padand concentrated in vacuo to half the volume. The residue was madeacidic with 2M HCl and then washed with toluene (2×10 mL). The aqueousphase was saturated with K₂CO₃ and extracted with EtOAc (3×20 mL),washed with brine, dried over Na₂SO₄ and concentrated in vacuo. Theresidue was purified by column chromatography [silica gel,iso-hexane/acetone (1:1)] to give 0.131 g (66%) of 8.

IR (film) ν_(max) 2238 cm⁻¹. ¹H NMR (CDCl₃, 270 MHz) δ 8.43 (br s, 1H),7.65 (dd, J=8.0; 2.1 Hz, 1H), 7.33 (d, J=8.1 Hz, 1H), 4.05 (br s, 1H),3.23-3.16 (m, 1H), 3.05 (app t, 1H), 2.31-2.21 (m, 1H), 2.18-2.07 (m,1H), 2.11 (s, 3H), 1.94-1.60 (m, 3H), 1.64 (s, 6H); ¹³C NMR (CDCl₃, 68MHz) δ 149.6, 141.9, 138.2, 135.4, 127.2, 94.5, 81.2, 68.8, 65.0, 57.1,40.5, 35.2, 31.4, 22.6. MS (EI, 70 eV) m/z 244 (M⁺) Anal. Calcd. forC₁₅H₂₀N₂O: C, 73.74; H, 8.25; N, 11.46%. Found: C, 73.56; H, 8.36; N,11.40%; [α]_(D) ^(rt)=−172.0 (c 1, MeOH).

(S)-2-Ethynyl-5-(1-methyl-2-pyrrolidinyl)pyridine (9).

Compound 8 (0.12 g, 0.5 mmol) and NaH as a 60% dispersion in mineral oil(0.005 g, 0.13 mmol) were dissolved in dry toluene (10 mL). The stirredsolution was slowly distilled until the boiling point of the distillatereached 110° C. The rest of the toluene was evaporated in vacuo. Theresidue was chromatographed [SiO₂, CHCl₃/MeOH, (10:1)] to give 0.062 g,(67%) of 9 as a yellow oil.

¹H NMR (CDCl₃, 270 MHz) δ 8.49 (d, J=2.2 Hz, 1H), 7.67 (dd, J=8.0; 2.1Hz, 1H), 7.43 (d, J=7.9 Hz, 1H), 3.25-3.18 (m, 1H), 3.11-3.03 (m, 2H),2.34-2.24 (m, 1H), 2.23-2.09 (m, 1H), 2.14 (s, 3H), 1.98-1.60 (m, 3H);¹³C NMR (CDCl₃, 68 MHz) δ 149.9, 141.2, 139.2, 135.2, 127.5, 83.0, 76.9,68.8, 57.1, 40.5, 35.4, 22.8. MS (EI, 70 eV) m/z 186 (M⁺) Anal. Calcd.for C₁₂H₁₄N₂: C, 77.39; H, 7.58; N, 15.04%. Found: C, 77.29; H, 7.44; N,14.89%; [α]_(D) ^(rt)=−148.5 (c 1, MeOH).

(S)5-(1-Methyl-2-pyrrolidinyl)-2-pyridinylpropiolic Acid (10).

A solution of 9 (0.053 g, 0.3 mmol) in THF (8 mL) was cooled to −78° C.and BuLi (1.6M solution in hexane, 0.2 mL, 0.32 mmol) was added. Thereaction mixture was stirred for 0.5 h at −78° C. and then CO₂ gas wasadded. After an additional 1 h at −78° C. the reaction mixture wasallowed to warm to room temperature. THF was evaporated in vacuo and theresidue was purified by column chromatography [silica gel, CHCl₃/MeOH,(1:1)]; yield 0.04 g, (87% based on recovered 9) of 10.

¹H NMR (CD₃OD, 270 MHz) δ 8.48 (d, J=1.8 Hz, 1H), 7.84 (dd, J=8.1; 2.2Hz, 1H), 7.59 (d, J=8.1 Hz, 1H), 3.28-3.20 (m, 2H), 2.44-2.39 (m, 1H),2.31-2.21 (m, 1H), 2.18 (s, 3H), 2.01-1.68 (m, 3H); ¹³C NMR (CD₃OD, 68MHz) δ 160.6, 150.6, 142.4, 140.3, 137.6, 129.2, 87.2, 78.3, 70.0, 58.0,40.8, 35.9, 23.5; [α]_(D) ^(rt)=−42.0 (c 0.5, MeOH).

What is claimed is:
 1. A method of producing a 6-substituted(S)-nicotine derivative with the formula (III),

wherein R is an optionally substituted alkyl, alkenyl, alkynyl, selectedfrom the group consisting of —X—Y—Z—O wherein X is —C≡C— or —C═C— or—CH₂—; Y is —(C H₂)_(k)— or —(CH₂)_(m)—C₆H₁₀—(CH₂)_(n)— or—(CH₂)_(m)—C₈H₄—(CH₂)_(n)— wherein k=0-20, m=0-6, and n=0-6, when Z is—NH— and Q is H or a carrier protein, and X is —C≡C— or —C═C— or —CH₂—,Y is —(CH₂)_(m)—C₆H₁₀—(CH₂)_(n)— or —(CH₂)_(m)—C₆H₄—(CH₂)_(n)— whereinm=0-6, and n=0-6, when Z is —CO—and Q is —OH or a carrier protein, and Xis —C^(o)C— or —C=C—, Z is —CO— and Q is —OH or a carrier protein, whenY is —(CH₂)_(k) wherein k=0-20, optionally coupled to a carrier protein,comprising the steps of a) reacting (S)-nicotine-N1-oxide with anorganic nitrogen base A, selected from the grow, consisting oftrialkylamine, dialkylbenzylamine, dialkylcyclohexylamine and pyridinein which the alkyl groups may be individually selected from lower alkylgroups, and an electrophilic compound selected from the group consistingof an arylsulphonate, a chloride and a lower alkylcarboxylate,optionally in the presence of an organic solvents to produce a(S)-nicotine derivative with the formula

wherein A represents a cationic radical of the organic nitrogen base,and Y represents an anion formed by the electrophilic compound, b)reacting the compound (I) with a nucleophilic reagent selected from thegroup consisting of halogenating agents to produce the (S)-nicotinederivative with the formula

wherein Nu represents the nucleophile, and reacting the compound (II)with an optionally substituted alkyn to produce the 6-substituted(S)-nicotine derivative with the formula (III) wherein R is theoptionally substituted alkyn group, followed by the optional steps ofhydrogenation of the triple bond of the alkyne to produce a compoundwith the formula (III) wherein R is the alkyl or alkenyl group,whereupon the compound (III) is optionally coupled via the terminalcarboxylic acid or amine group to a carrier protein.
 2. Method accordingto claim 1, wherein A represents an organic nitrogen base selected fromthe group consisting of: trialkylamine, dialkylbenzylamine,dialkylcyclohexylamine and pyridine in which the alkyl groups may beindividually selected from lower alkyl groups, and Y represents anarylsulphonate ion, a chloride ion or a lower alkylcarboxylate ion. 3.Method according to claim 1, wherein A represents a group selected fromthe group consisting of trimethylamine, triethylamine, tripropylamine,tributylamine, , N-dimethylbenzylamine, N,N-diethylbenzylamine,N,N-dimethylcyclohexylamine and N, N-diethylcyclohexylamine.
 4. Methodaccording to claim 2, wherein the nucleophilic reagent is selected fromthe group consisting of halogenating agents.
 5. Method according toclaim 3, wherein the nucleophilic reagent is selected from the groupconsisting of halogenating agents.